(CNN) -- They were crowded into a small rubber boat and pushed out to sea. Like so many other similar journeys, not everyone made it.

Showing signs of physical and mental trauma, 167 migrants, most from sub-Saharan Africa, were rescued off the northwest coast of Libya on Tuesday.

Another 13 -- including two pregnant women and a couple whose four children survived -- perished just 24 hours after setting off on a boat bound for Europe.

Early on in the rescue operation when Spanish NGO Proactiva Open Arms started to move the migrants out of the boat and into the safety of the rescue craft, they found bodies strewn across the bottom of the vessel.

"We are here to rescue people... and when you realize people died, you are there, you know their real situation, you feel the strong reality of the situation," Proactiva Open Arms mission leader Riccardo Gatti told CNN.

Barcelona, Spain — When Gagandeep Singh Khalsa first arrived in Barcelona from Punjab in India, people would point at him and whisper behind his back. It took him time to settle and it wasn’t until he began speaking the regional language that he truly felt “Catalan.”

"Santi Palacios, an independent Spanish photojournalist on assignment for the Associated Press, was embedded with Proactiva Open Arms, a Spanish rescue group begun by volunteer lifeguards who responded to the historic influx of asylum-seekers on the shores of Greece two years ago. With rough seas early on July 25, Palacios thought it could be a quiet day. But close to 11 a.m., a call came in about a dire situation 12 miles away. The vessel, named Open Arms, dispatched two speed boats that raced to the scene.

“We could very easily see that something was wrong, that something was not normal,” Palacios told TIME in the hours after the scene unfolded. The rescuers attempted to bring calm and distributed life jackets before disembarkation could begin. “It wasn’t until we took these four kids with us on our speed boat—and one woman to take care of them—that we really started hearing there were bodies inside.”

The migrants arrive by the hundreds on the beaches of the Greek island of Lesbos. And in their eagerness to move on, they leave behind belongings they carried on their backs.

The people fleeing war and poverty, mostly from Syria but also from Afghanistan, Iraq or Pakistan, turn up from the Turkish coasts after crossing rough seas on precarious rubber dinghies. This northeastern Greek island has become one the main entry points to Europe for refugees this year. More than 1,000 people arrive every day to the beaches on the north of the island, by now a dramatic routine.

The beach arrivals always chaotic, especially in bad weather. Children and adults jump off the dinghies as they approach the shore, desperate to reach land as soon as possible. On their backs, they carry the few personal belongings they managed to take on the journey. Some of them end up on the beach.